CYAICRSep 5, 2025

User Privacy and Large Language Models: An Analysis of Frontier Developers' Privacy Policies

arXiv:2509.05382v114 citationsh-index: 13Proceedings of the AAAI/ACM Conference on AI, Ethics, and Society
Originality Synthesis-oriented
AI Analysis

This addresses privacy risks for users of LLM-powered chatbots, revealing widespread data practices that lack consent and security, with incremental analysis based on existing legal frameworks.

The paper analyzed privacy policies of six U.S. frontier AI developers to understand how they use user chat data for training large language models, finding that all six use this data by default, some retain it indefinitely, and four include children's data, highlighting transparency gaps.

Hundreds of millions of people now regularly interact with large language models via chatbots. Model developers are eager to acquire new sources of high-quality training data as they race to improve model capabilities and win market share. This paper analyzes the privacy policies of six U.S. frontier AI developers to understand how they use their users' chats to train models. Drawing primarily on the California Consumer Privacy Act, we develop a novel qualitative coding schema that we apply to each developer's relevant privacy policies to compare data collection and use practices across the six companies. We find that all six developers appear to employ their users' chat data to train and improve their models by default, and that some retain this data indefinitely. Developers may collect and train on personal information disclosed in chats, including sensitive information such as biometric and health data, as well as files uploaded by users. Four of the six companies we examined appear to include children's chat data for model training, as well as customer data from other products. On the whole, developers' privacy policies often lack essential information about their practices, highlighting the need for greater transparency and accountability. We address the implications of users' lack of consent for the use of their chat data for model training, data security issues arising from indefinite chat data retention, and training on children's chat data. We conclude by providing recommendations to policymakers and developers to address the data privacy challenges posed by LLM-powered chatbots.

Foundations

The foundational work for this paper's niche, ranked by how specifically the neighbourhood builds on it — not by global fame.

Your Notes